Locally Advanced Rectal Cancer: New Neoadjuvant Strategies and Total Neoadjuvant Therapy

Abstract

Treatment strategies for locally advanced rectal cancer are changing significantly. The treatment recommended in German guidelines for locally advanced tumors of neoadjuvant radio(chemo)therapy (RChT), followed by surgery and, if necessary, adjuvant therapy, are increasingly be abandoned in favor of the following concepts: (i) prolonged neoadjuvant therapy (i.e. "more chemotherapy before resection", referred to as total neoadjuvant therapy, TNT); (ii) organ preservation in patients with a complete clinical response after neoadjuvant radiochemotherapy. (iii) omission of radiotherapy in tumors with a low risk of local recurrence; (iv) definitive treatment with immunotherapy (checkpoint inhibitors) for patients with a primary harboring microsatellite instability (MSI). Herein, current strategies and study concepts are to be discussed based on the guideline-based status quo.